In search of dark energy: Observing the expanding universe
with SCHOTT specialty glass
Spectrographs in Hobby–Eberly Telescope Dark Energy Experiment
composed of BOROFLOAT® glass
Jena (Germany), June 11th, 2015 – Specialty glass plays a key role in uncovering the
far-reaching answers of space. For HEDTEX (Hobby–Eberly Telescope Dark Energy
Experiment) at Austin McDonald Observatory (University of Texas at Austin), 150
state-of-the-art spectrographs will serve as the eyes into the universe’s distant past to
map the three-dimensional positions of one million galaxies. These spectrographs are
using optical mirrors based on BOROFLOAT® glass – the floated borosilicate glass
made by specialty glass expert SCHOTT. They will capture the full spectrum of light,
measure the distances between galaxies at different times in the early universe, and
reveal its composition. With those measurements, scientists can deduce the rate of
the universe’s expansion and further understand the physics of dark energy.
BOROFLOAT®’s exceptionally high transparency, outstanding visual quality and optical
clarity, and its outstanding thermal resistance are the key performance features helping to
observe the universe. The very good temperature stability of this glass is crucial to the
HETDEX project because the Hobby-Eberly Telescope, the world’s third largest optical
telescope, located more than 6,600 feet above sea level, experiences seasonal temperature
and weather fluctuations throughout the year, including snow in the winter and hot sunshine
throughout the summer. Thanks to the extremely low coefficient of thermal expansion,
BOROFLOAT® resists the challenging expansion and contraction forces that such change of
temperatures would typically cause, ensuring high resolution and consistency in researchers’
observation results.
Additionally, SCHOTT’s specialty glass boasts high chemical durability and excellent
mechanical strength mainly due to the addition of higher amounts of boron oxide in its
composition, which strengthens the chemical bonds within the glass network. The added
boron oxide gives BOROFLOAT® glass a low light refraction behavior, which together with
the material’s superior transmission is a key requirement for precise spectrograph
measurement results.
Furthermore, light transmission in glasses will be significantly influenced by iron oxide
impurity levels. BOROFLOAT® glass is made of pure raw materials, resulting in an extremely
low-iron impurity level for float glasses. The sum of it guarantees exceptionally high
transmission values. In fact BOROFLOAT® is the industrial glass with the lowest level of iron
impurity of all float glass materials in the market.
“The HETDEX project holds the key to unlocking the secrets of the cosmos. SCHOTT’s glass
will serve as a significant material as researchers gaze into the earliest millennia in time to
PR 067_2015
Page 1 of 3
better understand the forces that continue to shape the universe”, said Dan Bukaty Jr.,
President of Precision Glass and Optics Inc., USA, the company that processes
BOROFLOAT® to create the optical mirrors.
For more information visit: https://www.youtube.com/watch?v=BnM-x6-gneg
®
BOROFLOAT is a registered trademark of SCHOTT AG.
Photo download link: http://www.schott.com/english/news/press.html?NID=com4711
Prototype of the spectrograph used for HEDTEX: It uses optical mirrors based on BOROFLOAT
glass from SCHOTT. Source: Courtesy of Martin Harris/McDonald.
®
“The HETDEX project holds the key to unlocking the secrets of the cosmos. SCHOTT’s
®
BOROFLOAT glass will serve as a significant material as researchers gaze into the earliest millennia
in time to better understand the forces that continue to shape the universe”, said Dan Bukaty Jr.,
®
President of Precision Glass and Optics Inc., USA, the company that processes BOROFLOAT to
create the optical mirrors. Photo: SCHOTT.
PR 067_2015
Page 2 of 3
®
Post-processing of SCHOTT’s BOROFLOAT floated borosilicate glass to achieve the smooth surface
needed to create optical mirrors. Photo: SCHOTT.
SCHOTT is a leading international technology group in the areas of specialty glass and glassceramics. The company has more than 130 years of outstanding development, materials and
technology expertise and offers a broad portfolio of high-quality products. SCHOTT is an innovative
enabler for many industries, including the home appliance, pharmaceutical, electronics, optics,
automotive and aviation industries. SCHOTT strives to play an important part of everyone’s life and is
committed to innovation and sustainable success. The group maintains a global presence with
production sites and sales offices in 35 countries. With its workforce of approximately 15,400
employees, sales of 1.87 billion euros were generated in fiscal year 2013/2014. The parent company,
SCHOTT AG, has its headquarters in Mainz (Germany) and is solely owned by the Carl Zeiss
Foundation. As a foundation company, SCHOTT assumes special responsibility for its employees,
society and the environment. www.schott.com
Press contact:
SCHOTT AG
Dr. Haike Frank
Public Relations Manager
Hattenbergstrasse 10, 55122 Mainz, Germany
Phone: +49 (0)6131 / 66-4088
e-mail: [email protected]
PR 067_2015
Page 3 of 3